Morata, David Luiz & the Chelsea stars in danger of missing the World Cup

Alvaro Morata was left out of Julen Lopetegui's Spain squad for the first time since he joined Chelsea when his bad form hit ahead of the selection for the games against Germany and Argentina in March. 

The Chelsea striker was key in the qualification campaign for Spain, but he was described as "frustrated" by his friend Marcos Alonso, who earned his first call-up for those friendlies. 

Lopetegui picked Diego Costa, Rodrigo and Iago Aspas ahead of Morata, but offered some encouraging words to the Chelsea man. 

"There are many players that deserve to be in the national team but are not here," Lopetegui told Onda Cero radio. "Alvaro has gone through a spell with injuries and that is why we considered it best for him not to be on this list.

"I did call Alvaro before giving the list to tell him that he was not going to come. It's my duty and I do it also with many other players. It's normal that all the players want to come and feel frustrated if they don't."

David Luiz has not played for Brazil since March 2016 as Tite moves the Chelsea centre-back out of his favoured group, with a call now looking very unlikely. 

The 30-year-old was struggling to be selected even when he was in top form, but he has since seen his chronic knee injury worsen, as his team's form also drops. 

Luiz is fifth or sixth on the pecking order and his best hope may be that a new coach comes in and reinstates him into the reckoning after the tournament is done. 

Tiemoue Bakayoko's debut season at Chelsea has been nothing short of a disaster since he made his £40 million move from Monaco last summer. 

Antonio Conte tried hard to integrate Bakayoko into his starting line-up, but his good performances were outnumbered by his poor ones and he is now often seen on the bench. 

His sending-off against Watford was pivotal and it could go down as one of the Premier League's worst-ever displays. 

This poor form, coupled with an immense competition for places with France, means it is almost certain that Bakayoko won't build upon his solitary cap for his national team in the summer. 

Gary Cahill is used to being an ever-present in both Chelsea's and England's squads but things have changed for him recently. 

The good form of Antonio Rudiger has meant that Chelsea's captain has often been left on the bench, which has become a big problem for Cahill in a World Cup year. 

Gareth Southgate admitted it was hard to leave out Cahill, who still holds some hope of getting back in to the Russia 2018 squad, for the recent games against the Netherlands and Italy. 

Southgate said: "Tarkowski and Mawson are players you want to look at for now and beyond the summer. I want to see [Eric] Dier in a back three, too. It’s a very difficult call because Gary has played a lot of qualifiers and is a great guy."

It is fair to say that Cesc Fabregas already has a legacy as a legend for Spain after providing the vital assist to the most important goal in his national team's history. 

He is Spain's eighth most-capped player of all time (110) and has won a World Cup, along with two European Championships. 

However, Julen Lopetegui has completely sidelined Fabregas during his time in the national team, with the country having an abundance of creative midfield talent. 

It is looking hard for Fabregas to break back into the squad, but he told Goal back in March that he hasn't given up just yet. 

"I am not a player who throws the towel. I have a small hope, in some way, but I know it is hard [to get called up for the World Cup]," he said. "I haven't received any calls or been included in any team list for all this time.

"Anyway, I don't think about it because I keep my focus on performing here [at Chelsea], but maybe it wouldn't be strange to call someone who first came into the team 15 years ago. It is obvious that they already know me but it would be nice to get in.

"I am focusing now on my club because, in the end, if you don't do right things in your club, it is impossible to receive the call. And if it finally arrives, perfect. If not, I will support the team from home."

Ross Barkley was named in the last England World Cup squad in Brazil, but he is looking a long way out of the selection picture, having also missed Euro 2016. 

The former Everton man was out for around nine months after undergoing a hamstring operation before completing his £15m move to Chelsea in January. 

He has since made only sporadic appearances, suffering several minor injuries as he bids for a regular return to first-team football. 

Antonio Conte currently has Barkley playing in Under-23s football to improve his match fitness, but it doesn't look like he will be in top form ahead of the World Cup. 

Pedro has not played for Spain since October and, after a brilliant year last season in Chelsea's run to the title, he has struggled this time around. 

The 30-year-old has had a few small injuries and he has seen Willian take his place in the starting line-up after being unable to show his best form. 

Lopetegui could leave out a number of Chelsea players in the summer and Pedro is looking likely to be one of those given the embarrassment of riches for Spain in most positions on the pitch. 

Danny Drinkwater has been a late bloomer in his career after leaving Manchester United to play for Leicester City in the Championship. 

He earned wider recognition and an England call-up after Leicester shocked the world by winning the Premier League in 2016, and it was hoped that a move to Chelsea could put him further into the international picture. 

However, his £35 million move has so far not been a success and time is running out on his World Cup hopes, despite his country crying out for a central midfielder with his attributes. 

Drinkwater has yet to play in an international tournament and his move to play under Antonio Conte, so far, hasn't helped his chances. 

Marcos Alonso's story is perhaps the most positive of those players on this list, but he still faces a huge battle to convince Julen Lopetegui to select him. 

The 27-year-old has been struggling to compete for years to get that first call-up, with his national team having so much talent in his position. 

His consistent displays with Chelsea eventually saw him make his debut in March against Argentina. Alonso made history that night by becoming the first third generation international to play for Spain, with both his father and grandfather having played for their country before him. 

Alonso remains a slight outsider for the Spain squad but he has given himself a chance amid huge competition.